Stack switch construction



Jan. 16, 1940. SHAW STACK swmm CONSTRUCTION Filed Dec. 14, 1937 Patented Jan. 16, 1940 UNITED STATES PATENT OFFICE Electric Switch 00., tion of Iowa Goshen, Ind., a corpora- Application December 14, 1937, Serial No. 179,708

6 Claims.

One object of my present invention is to provide a stack switch construction having a novel speed ratchet arrangement to increase the operating efficiency of the stack switch, the mechanism therefor being comparatively simple and inexpensive to manufacture.

Aiurther object is to provide a stack switch construction in which the heat of the stack is dissipated to atmosphere to such an extent before it reaches the housing of the stack switch that the housing and the mechanism therein can be retained comparatively cool even at high stack temperatures.

Another object is to provide a stack switch comprising a housing to which a radiation shield is secured in spaced relationship, a tube extending from the radiation shield into the stack and supporting the temperature responsive element therein whereby the heat conducted through the wall of the stack by the supporting tube is radiated or dissipated by the radiation shield before it reachesthe switch housing.

A further object is to provide within the switch housing, a switch which is operated by an oscillatable rod extending from the temperature responsive elementthrough the supporting tube and into the switch housing, connection being made between the oscillatable rod and-the switch contacts by an arrangement which substantially immediately separates or engages the contacts upon initial movement of the rod in either direction, the connection between the contacts and the rod being in the form of a disk on the rod, 2. spring pressed ball engaging the notched periphery of the disk and an arm with which the ball is connected, the arm in turn being operatively connected with the switch contacts.

A further object is to provide an operative connection between the rod and thecontacts which 4% connection is of the slipping type without, however, accomplishing the slip connection by Eric. tionally engaged surfaces so that the parts of my connection are mechanically'correct and not subject to variation after installation as experienced with friction types of clutches in stack switches.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my stack switch construction, whereby the objects contemplated are attained, as hereinafter more fully set forth,-pointed out in my claims and illustrated in the accompanying drawing, in which:

Figure 1 is a perspective view of a stack switch structure embodying my invention.

Figure 2 is an enlarged sectional view on the line 2-2 of Figure 1.

Figure 2a is a perspective view of a spring washer included in the make-up of my stack switch.

Figure 3 is a front elevational view as along the line 33 of Figure 2 showing the operative connection with the oscillatable rod and switch contacts.

Figure 3a is an enlarged view of a fragmentary part of Figure 3; and

Figure 4 is a plan view of the stack switch on a reduced scale showing it mounted relative to a stack or the like.

On the accompanying drawing I have used the reference character H to indicate generally a' housing, and C a removable cover therefor. A radiation shield R is mounted on the back of the housing and a supporting tube '1 extends therefrom. On the inner end of the tube '1 an element E is provided which is responsive to temperature. The element E for instance, may be a coil of bi-metal of suitable composition to Withstand stack temperatures. In Figure 4 I illustrate a stack S to which a flange ID has been secured for the purpose of supporting the tube T.

The radiation shield R is connected to the back of the housing H by post-like connector elements $2. The tube T may be connected to the radiation shield R in any suitable manner. By way'of illustration 1 illustrate slot and tongue connections at i3. The element E is responsive to the temperature in the stack S. The tube T conducts the heat in the stack to the radiation shield R. The-radiation shield being spaced from the housing H causes the heat to be dissipated or radiated to atmosphere instead of being transmitted on to the housing H where it would heat it and its contents to an undesirable extent. Thus the radiation shield serves an important function in keeping the housing H cool. The dissipation of the heat from the radiation shield is materially augmented by the spacing of the v "shield from the housing by the post-like supports H as this provides a space thru which air can circulate to carry the heat away from the radiation shield.

One end of the temperature responsive element E is secured to the tube T as by a screw H. The

other end is connected by a screw 15 to one end of a. rod 16. The rod l6 extends through the tube T and the radiation shield R. and into the housing H. Within the housing H a panel ll, preferably of insulating material is provided. A sleeve l8 extends therethrough and the rod I 6 extends through the sleeve. A bracket I8 is mounted on the panel l1 and carries one or more stationary contacts 20. A second bracket 2| is mounted on v switch arm 22. The cover 25 is mounted on the panel H as by a screw 26.

For actuating the switch contacts I provide an elongated arm 21 preferably formed of insulating material and having its upper end swingably mounted on the rod IS. The lower end of the arm has a comparatively wide slot 28 to straddle the bracket 2| while its extreme lower end isprovided with a relatively narrow slot 29 receiving a lateral extension 30 of the leaf spring 22 intermediate the ends of the leaf spring. H

A bracket 3| is secured as by rivets 32 to the arm 21. The bracket 3| has a ball seat 33. A ball 34 is adapted to be seated therein by a spring 35. The spring 35 is interposed between an extension 35 of the bracket 3| and a thimble 31 in which the ball 34 is seated. r

A disk 38 is secured to the rod l6 as by a pin 38. The disk 38 is located between the arm 21 and an extension 40 of the bracket 3|. The extension 40 is provided with a perforation 4| receiving the rod It so that the bracket is swingable relative to the rod. The bracket extension 40 is provided with three indentations 42 engag-- ing one face of the disk 38 while a spring washer 43 (shown in perspective in Figure 2a.) is interposed between the other face thereof and the arm 21. The washer 43 is made of spring bronze or the like and bent across the middle as shown. The Washer." and the indentations 42 take up lost motion between the parts and the three indentations reduce frictional engagement as caused by the spring washer to a minimum.

The periphery of the disk 38 is notched or serrated thus-providing spaced teeth 44. To avoid confusion on the drawing, the teeth 44 are relatively enlarged in Figure 3 and Figure 3a is included to better show the sizes and spacing of the teeth relative to the ball 34. These teeth coact with the ball 34 and the spacing between the disk 38 and the seat 33 for the ball is such that the ball is retained slightly off the seat as best shown in Figure 3a. The seat prevents dislodgement of the ball from the seat when the parts are ,disassembled and also prevents excessive movement of the ball laterally of the arm 21 during operation. By having the disk keep the ball slightly off the seat the proper ratchet action is obtained for operating the switch.

My construction enables the use of a comparatively small diameter notched disk yet the benefit of a comparatively large one is secured. Large arm'2'l. By using a balll type contact at 34, the teeth 44 of the disk/ 38 can be made relatively close together and the proper slip. action secured. All of the advantages obtained are possible without the necessity of making a switch with many and expensive parts.

Some changes may be made in the construction and arrangement of the parts of'my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a stack switch construction, switch contacts and means for actuating said contacts comprising a rotatable rod, an element responsive to temperature for oscillating said rod in response to increase and decrease in the temperature to which said element is' responsive and an operative connection between said rod and said switch contacts comprising an elongated arm having a pair'- -of ports freely swingable on said rod, the outer end thereof being connected with said switch contacts to separate them from each other when the elongated arm swings in one direction and engage them with each other when said elongated arm swings in an opposite direction,

a disk on said rod between said parts and having a radius which is substantially less than the" length of said arm on said rod, the periphery of said disk being notched, a, ball element carried by said arm and engaged with said notched periphery and resilient means acting at substantially right angles to the axis of said rod and opposed by said pair of parts on said rod, said resilient means causing such engagement.

2. In a stack switch construction, switch contacts and means for actuating said contacts comprising a rotatable rod, an element responsive swings in an opposite direction, a disk on said.

rod, the periphery of said disk being notched, a bracket carried by said arm having a first portion also pivoted on said rod and having a second portion adjacent the periphery of said disk, said disk being located on said rod between said arm and said first portion of said bracket, a ball seat in said second portion, a ball projecting therethrough and engaging the notched periphery of said disk and a spring interposed between a third portion of said bracket and said ball to urge the ball toward engagement with the disk.

3. In a switch structure, a stationary contact, a bracket, a leaf spring anchored at one end thereon and having a contact carried thereby for engagement with and disengagement from said stationary contact and means for actuating said leaf spring comprising an element responsive to temperature, an arm swingably mounted, said arm having a slot therein, through which said bracket extends, said slot having a constricted portion receiving a portion of said leaf spring intermediate said stationary contact and the anchored end of the spring, a disk movable by said temperature responsive element and having a notched .periph ry and a ball element carried by said arm d resiliently engaged with said notched periphery of said disk.

4. In a, switch construction of the character U disclosed, a panel, an oscillatable rod projecting aroma therethrough, a temperature responsive element for oscillating said rod, a pair of brackets mounted on said panel, a stationary contact carried by one of said brackets, a leaf spring carried by the other bracket and having a contact engageable with said stationary contact, an arm swingable on said rod and operatively connected with said leaf spring intermediate the ends thereof, a bracket on said arm having a portion journaled on said rod, a disk on said rod between said arm and said bracket portion, said disk having a notched periphery and a spring urged friction member carried by said bracket and engageable with said-notched periphery.

5. In a switch construction of the character disclosed, an oscillatable rod, a temperature responsive element for oscillating said rod, a stationary contact, a leaf spring having a contact naled on said rod, a disk on said rod between.

said arm and said bracket portion, said disk having a notched periphery, said bracket on said v arm having a ball seat, a ball projecting therethrough and engaging said notched periphery, said ball being slightly spaced from said seat and a spring biasing said ball toward said seat, the direction of bias being substantially radially toward said rod and opposed by said arm and said portion thereon. a

6. In a switch construction of the character disclosed, a. stationary contact, a leaf spring anchored at one end and having a contact on its other end for engagement and disengagement relative to said stationary contact and means for actuating said leaf spring comprising a rotatable rod, an element responsive to temperature for oscillating said rod in response to increase and decrease in the temperature to which said element is responsive, a forked arm rotatable on said rod, said arm being operatively connected with said leaf spring, a disk on said rod located in the bifurcation of said forked arm and having a notched periphery and a ball element carried by said arm and resiliently engaged with said notched periphery.

march in. SHAW. 

